Roaming between native wifi and wired access point

[NYZack]

This is a naive question but one that I haven't seen discussed; I doubt it is unique to Asus routers (I've observed the same phenomenon with other routers), and I'm surprised more people don't comment on it.

My setup is this: I have an Asus AC-68U router running Asus Merlin. In addition to using the router's native wifi, I have two wifi access points directly wired to its ethernet ports for wifi coverage of remote points in my house. All of the wifi networks share the same SSIDs and authentication parameters, but they use different channels. I can roam from one to another without a problem. They are just dumb access points and rely on the 68U for DHCP, firewall, etc.

The problem I note is that certain apps on my smartphone (Google Hangouts is the worst offender; the Logitech Harmony Android app is another) seem to transiently lose connectivity when I roam from the router's wifi to one of the remote access points, though my phone maintains Internet access (e.g., I can access websites); eventually, however, everything sorts itself out by itself. My thought (sorry if this turns out to be an ignorant hypothesis) is that when the router receives a packet destined for my phone, which had initially connected over the router's native wifi, it routes the packet over its native wifi rather than routing it via the wired LAN to the remote AP my phone has roamed to. That is, it doesn't seem to know my phone has roamed from the router's wireless connection to (from the router's point of view) a wired connection. Eventually, the phone (or the app) makes itself known on the new interface, and everything works fine - maybe the routing table gets updated?

Is this explanation plausible? Any solution to this?

 

[thiggins]

There is no routing involved with AP roaming; everything is on the same network. But it takes time to make the switch from one AP to another. Some devices are faster than others at making the swith

Media apps rely on packets arriving on time and in order to maintain the media stream. Some apps drop the connection if the stream is dropped even for a short time.

Some newer "mesh" WiFi systems are better with roaming than others. You might try different APs or check to see if there are any roaming assistance settings.

 

[NYZack]

There is no routing involved with AP roaming; everything is on the same network. But it takes time to make the switch from one AP to another. Some devices are faster than others at making the swith

Media apps rely on packets arriving on time and in order to maintain the media stream. Some apps drop the connection if the stream is dropped even for a short time.

Some newer "mesh" WiFi systems are better with roaming than others. You might try different APs or check to see if there are any roaming assistance settings.

The issue is not with the time it takes to switch AP's. That happens without a problem. My problem is that certain apps fail to work for some time while roaming between APs - but only some apps. For instance, I can browse to a new site on Chrome immediately, but Hangouts will not receive a new text for a while.

When the router receives a packet destined for a particular IP address on the local network, does it really broadcast that packet to all hard-wired and wifi devices on the LAN? Or does it have some knowledge of where that device was last seen? If the router knows an IP address was last seen on ethernet #1, for instance, doesn't it just send a packet for that address to ethernet #1 rather than broadcasting it on wifi and to the other ethernet connections? If so, isn't that possibly the root of my problem, which involves devices roaming from wifi to hard-wired connections and then between different hard-wired connections?

 

[TaagMan]

I have the same setup as you. With the same model, and I found out it's a bug in the hardware acceleration. Try and disable NAT acceleration under LAN>Switch Control.

I'm pretty sure that's part of something that Merlin can't fix. Because it's closed source... the NAT acceleration.

 

[coxhaus]

The issue is not with the time it takes to switch AP's. That happens without a problem. My problem is that certain apps fail to work for some time while roaming between APs - but only some apps. For instance, I can browse to a new site on Chrome immediately, but Hangouts will not receive a new text for a while.

When the router receives a packet destined for a particular IP address on the local network, does it really broadcast that packet to all hard-wired and wifi devices on the LAN? Or does it have some knowledge of where that device was last seen? If the router knows an IP address was last seen on ethernet #1, for instance, doesn't it just send a packet for that address to ethernet #1 rather than broadcasting it on wifi and to the other ethernet connections? If so, isn't that possibly the root of my problem, which involves devices roaming from wifi to hard-wired connections and then between different hard-wired connections?

What you are talking about does not happen at layer 3 the IP level. So no IP is involved It is at a lower level. And yes layer 3 is part of the complete packet.